The present invention relates to an imprinting machine, and more particularly to a machine for imprinting indicia on thermoplastic corrugated tubing as the tubing moves along its path of travel.
Generally the machinery for manufacturing thermoplastic corrugated tubing comprises an extruder having an annular die at the free end thereof for producing a hollow smooth-walled cylindrical extrudate. The smooth-walled extrudate is then fed into a continuously moving corrugator comprising a plurality of mold sections that mate with each other to form the molding zone of the corrugator. Air pressure is utilized to blow the soft, smooth-walled extrudate onto the configured mold surfaces of the corrugator to thereby form the corrugations in the tubing product. The tubing is then cooled, perforated if desired, and coiled or cut into lengths. The perforations may be in the form of slotted openings when the tubing is to be used for drainage purposes, or circular openings may be provided for septic leach bed applications.
It is desirable to provide the tubing with identifying indicia concerning such information as the day and year of manufacture, the particular location of manufacture, material specifications, etc. Such information is useful to the manufacturer and in some cases at least some of the above information may be required by local, state and/or federal agencies. For example, the Bureau of Reclamation requires that every ten feet of corrugated tubing be marked with the plant of manufacture, date, shift and lot number. Obviously such information is always changing and marking machinery capable of easy change of the indicia is necessary.